The invention is based on a keypad with individual keys made from transparent plastic. Keypads as used in telephone devices are already known in the art. A conventional telephone terminal contains a keypad part with individual numbers as well as keys which trigger defined functions. These special function keys are, for example, lettered or engraved on the keypad surfaces. In addition, conventional devices have keys whose function is freely programmable. In order to give the user information on the programmed function of the individual key, it is possible to write in a title block adjacent to the key. In order to guarantee the user the most simple use of his terminal, a number of function keys can be used. The number of function keys is limited due to their space requirements, as the freely programmable keys with their adjacent title blocks take up a large proportion of the surface of the device. In addition, conventional devices which contain lettered function keys are always designed for a certain language region. Thus different product lines are necessary to produce lettering in different languages.